The present invention relates, in general, to probe cards, and more particularly, to probe card probes and methods for manufacturing probe card probes.
In an effort to preclude packaging defective semiconductor chips or dice, semiconductor device manufacturers have developed techniques for testing semiconductor chips in both wafer and chip or die form. For example, Hasegawa teaches in U.S. Pat. No. 4,563,640, a fixed probe board for testing semiconductor wafer chips. The probe board comprises a multiplicity of probe needles mounted to a support base, wherein the configuration of probe needles matches an array of electrode pads spread around the periphery of the integrated device to be tested. Although this invention has provided a means for testing unencapsulated integrated devices, it is impractical for testing integrated devices having a large number of electrode pads spread across the surface of the integrated device, i.e., electrode pads configured in an area array. Further, the difference between the coefficients of thermal expansion of the probe board and the device under test may result in a high impedance contact between the probe needles and the electrode pads on the semiconductor device.
B. Leslie and F. Matta, in their paper "Membrane Probe Card Technology," presented at the 1988 International Test Conference, addressed the limitations of conventional probe cards. Moreover, they have described a probe card in which the probe needles were replaced with contact bumps formed on a flexible dielectric membrane. The contact bumps have limited compliance and rely upon the compliance of the membrane material both to conform vertically to variations in the pad heights and to wipe the pad surface laterally to make good electrical contact. In addition, a substantial force must be applied to the die under test in order to achieve good contact.
Accordingly, it would be advantageous to have compliant probe card probes capable of temporarily contacting bonding pads on semiconductor chips and a means for fabricating the probe card probes. The resiliency of the probe card probes should permit them to contact bonding pads of different heights without damaging the probe card probes or the semiconductor chips. It would be of further advantage for the probe card probes to have sufficient resiliency to preclude permanent deformation when contacting semiconductor chips.